Current practice in automotive carburetor testing processes requires that a carefully controlled blend of gasoline or other solvents be flowed through the carburetor fuel system to measure and adjust the carburetor fuel flow characteristics. In the quest for an alternative to the use of gasoline or other solvents in these processes, ordinary tap water was used as a test fluid. However, the water did not provide repeatable test data, apparently because its high surface tension does not permit adequate wetting of the various surfaces in the carburetor fuel system.
Thereafter, as set forth in U.S. Pat. No. 3,584,506 issued June 15, 1971 in the name of J. S. Smatko, aqueous solutions of several different wetting agents, having surface tension values substantially below that of water, were tested. Those tests indicated that solutions with high foaming tendencies also produce non-repeatable test data. However, solutions were found which did provide repeatable data, and as a result, it was concluded that a water-based test fluid suitable for use in a fuel system flow process should be characterized by a tendency to produce a foam height less than about 35 mm on the Dynamic Foam Tester.